1. Field of Invention
This invention relates to passive seatbelt systems and more particularly to passive seatbelt systems which automatically fasten and unfasten the restraining belt from a passenger.
2. Prior Art
Seatbelt systems restrain passengers and prevent them from colliding with dangerous objects during vehicular emergencies. As a result, such systems make it possible to achieve a conspicuous improvement in passenger safety. In spite of this fact, however, the percentage of passengers who wear seatbelts is extremely low because of the difficulty in donning seatbelts, etc. As a result, various types of passive seatbelt systems have been proposed which make it possible to automatically fasten the belt around the passenger after the passenger has seated himself in the vehicle.
Among these systems, passive seatbelt systems which automatically fasten the belt around the passenger and remove the belt from around the passenger by the use of the driving force of a motor, etc., to move a runner piece which anchors the outer end of the belt have been highly rated because of their reliable operation. In such passive seatbelt systems, the tension on the belt is transmitted to the vehicle body via the runner piece. It is therefore necessary that the guide rail which serves as a guide part for the runner piece be of sufficient strength. However, in cases where a large, strong guide rail is used, the projection of parts of the passive seatbelt system into the passenger compartment decreases the passenger space in the vehicle and is dangerous in that it increases the possibility of a passenger colliding with the projecting portions during a vehicular emergency.